91447910640 has 60 divisors (see below), whose sum is σ = 307112568984. Its totient is φ = 24386109312.

The previous prime is 91447910639. The next prime is 91447910657. The reversal of 91447910640 is 4601974419.

It is a tau number, because it is divible by the number of its divisors (60).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 63504774 + ... + 63506213.

Almost surely, 2^91447910640 is an apocalyptic number.

91447910640 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

91447910640 is an abundant number, since it is smaller than the sum of its proper divisors (215664658344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91447910640 is a wasteful number, since it uses less digits than its factorization.

91447910640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127011006 (or 127010997 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 91447910640 in words is "ninety-one billion, four hundred forty-seven million, nine hundred ten thousand, six hundred forty".